Telephone-exchange system



March 24, 1925. 1,531,025

L. POLlNKOWSKY TELEPHONE EXCHANGE SYSTEM Filed NOV. 17, 1919 3Sheets-Shree?, l

.g /Cl /04 I "Dv--o-cn H* L/po Po//n/fo Ws/y March 24, 1925. 1,531,025

L. PQLINKOWSKY TELEPHONE EXCHANGE SYSTEM 400 /DO//h/fo ws /gy March 24,1925. 1,531,025

l.. PoLlNKoWsKY TELEPHONE EXCHANGE SYSTEM Filed Nov. 17, 1919 bym /WJ/Patented Mar. 24, 1925.

UNITED STATES PATENT oFFicE.

LIPA POLINKOWSKY, F ANTWER-l?, BELGIUM,`ASSIGNOR TO IVESTERN ELECTRICCOM- PANY, INCORPORATED, OF NEW YORK, N. VY., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed November 17, 1919. Serial No, 338,441.

the selective switches, which serve to set up connections betweensulsscribers lines, are arranged to be controlled by register senders.Upon ythe initiation of a call on a subscribers line, an idle sender isautomatically asL sociated with suchy line and the calling subscriberproceeds to register the ldesi,`f gnation of the desired line on thesender taken for use. vAfter the register sender has been posi tioned,:it is then operative' to control the switches in accordance with therequired selections..

The object of the invention is the provision of an arrangement wherein,ifa register sender fails toA function properly or if a callingsubscriber is unable to control the setting thereof, said sender isautomatically associated with an opcrators position.

A feature of the invention resides iii theV provision of switching meanscommon to a plurality of register senders and arranged to associate anyone of such senders that does not function properly with an operatorsporsition.

Another feature is the provision of a common switching means for aplurality oi register senders so arranged that, when any register senderis taken for use andl the registration of the designation thereon isdelayed for a predetermined interval, said switching means automaticallyassociates such sender with an operators position. y

A further featurev of the invention relates to a signal arrangement atthe operators position, operated in accordance with the operation ofsaid switching means to identify to the operator the designation of theregister sender that has failed to progress in its lregular operation.

Other features contemplated by this invention will become apparentl fromthe following description and the appended claims.

In the drawings Figs. 1 to 3 taken in order from left to right',illustrate so much of a telephone exchange system as is necessary to anunderstanding of the invention.

Fig. 1 shows a subscribers line and also illustrates diagrammatically alirst line finder switch and a second line finder switch for extendingsaid line to the circuits of a first group selector in the exchange.Tothe right ot the broken Iline in `Fi`g. 1 there is shown the detailedcircuitsfof ay hunting switch which has access to a plurality ofregister senders together lwith a schematic illustration of thearrangement on the terminal h To the left bank of such hunting switch.ot the broken line 1n l" ig. 1 is shown an op erators position ina-distant exchange and a trunk circuit leading Yfrom the operators fposition to said hunting switch. l n f HFgs. and 3 show the detailedcircuits of a register sender forV controlling the operation otthe"group andv final selectory the'manner inwhich the several registersenders appear in the terminal bank ofy the limiting switch shown inFig. 1 Figs. 2 and f 3. further show the brushes and the talking circuit'ot' a first group selector switch and means for associatting aregistersender with L such switch when a calling line is extendedthereto. Fig. 4 is a schematic .illustration oic one of the registersenders together with a sender switch for associating the sender withthe selector switch. Y

In machine switching 'telephone `systems of thel full automatic typeemploying selective switches operatedY in accordance with the revertiveimpulse control principle, register sending mechanisms-are'provided inthe exchange for controlling the selective operations of such switches;Following the initiation of a call an idle one of these register sendersis automatically connected to the calling subscribers line ready to beset up by impulses transmitted from the calling substation in accordancewith the designationof the desired line.V It may happen that, upon anidle register sender being aslofi:

vvvtunable to proceed with the setting up of the register sender. Wherethe exchange or the satellite in the system is of small capacity theinstallation and maintenance of a trouble operators position in each ofsuch small exchanges is not warranted. Ac-

cordingly, as is contemplated by the present invention, the troubleoperators position is located in a` central exchange and trunk lines arep-rovided leading from the operators position to the smaller exchangesand satellites. Each of these trunk lines incoming from the operato-rsposition in the central exchange terminates in a hunting switch which isarranged to select automa-tically any one of a plurality ofregistersenders in which the unstandard condition exists.l These huntingswitchesrare so designed that if a call is initiated and the setting-upof the appropriated sender is notl proceeded within a predeterminedinterval of time, the hunting switch automatically selects such senderand Iassociates it with the operators position'in the distant exchange.yMoreovena talking connection is established betweenl the. callingsubscri'bers liney and the trouble o-peratorspositio-n in order thatthe-subscriber may inform the operator of the designation of the linewith which he desires to obtain connection. If the trouble is due tothesubscri'bers inability totransmit impulses to the exchange, theoperator, who is also provided with an impulse sender, is. enabled tolset-up the sender in accordance with the required designation and thecallfproceeds thereafter in the usual manner. If the sender has failedto function, t-he operator, 'who is given a visual signal indicating thedesignation of the particular L*sender concerned, informs a trouble...man ofr this fact who is then enabled toimmedia'tely locate andcorrect the unstandard condition. t'

The register sender shown in detail in` Figs. 2 and 3 appears in thehunting switch in terminals 226, 227, 228 and 229. These terminals-areshownas-tlie `5th set, counting from the left in the-,upper row in theschematic arrangement shown infFig. l. The second: register sender, aportion of which is sho-wn in Fig. 2, appears in the hunting switch interminals 235, 236, 237 and 238,

or the 9th set in the upper row in Fig. 1. The remaining registersenders to which the hunting switch has access appear in like manner inthe terminal 'bank of such switch. The lowermost terminal 239 of thefirst set, which indicates the nominal position of the limiting switch,is connected to ground. When the switch is taken for use the brush 129,after leaving its normal position, first engages the terminal 240 in thethird set. After the hunting switch passes over terminals 226, 227, 228and 229 individual to the first register sender, the brush 129 engages aterminal 241 similar to the terminal 240. After having passed the'terminals 235, 236, 237 and 238 individual to the second sender, thebrush 129 next engages a terniinal 248 and so on. The purpose of theterminals 240, 241, 248, etc., which are placed in advance of theterminal sets representing thesuccessive register senders, will be morefully explained hereinafter.

A plurality of sequence switches of the well-known construction is shownin the disclosure of this application for performing the variouscircuit-controlling operations. Where more than one sequence switchappears on the same sheet of the drawings, each such. sequence switchand the contacts controlled thereby are located within the same areabounded by broken lines.

A description in detailwill now be given of the operation of the systemwhen a call is extended from one subscribers line to another. Assume thesubscriber at the substationy 100 wishes'to obtain `a connection with asubscribersiline, the substation of which is shown at 300. The callingsub.- scriber upon removing his receiver from the switchhook initiatesin the usual manner the operation of a first line finder switch 101 anda second line finder switch 102 Whichg extend the calling line overconductors 103, 104 to the circuits of a first group selector switch,the brushes of which are illustrated at 306 and 307. The call havingbeen extended to the first group selector, certain circuit changes arebrought about thereat and a sender selector switch is started inoperation to select an .idle'v register sender and connect the same vtothe calling subscribers line. Referring to Fig.

4 `the sender selector switch is shown in the form of a sequence switch401 having contacts 402, 403, 404 and 405. The sender 400 villustratedschematically is associable through the contacts of the sender selectorswitch 401 with the circuit/40G leading to thefselector switch whosebrushes 407 and 408 are shown. The leads from the sender 400aremultiplied to appear in corresponding contacts of other senderselector switches as illustrated. Assuming that the register sendershown in Figs.' 2 and 3 is the one taken for use, this register .senderis then connected over leads 202, 203, 301, 302, 303 to the circuits ofthe first group selector switch. For a complete disclosure anddescription of the manner in which a register sender of this type isassociated by a sender selector with the first group selector circuits,reference is made to the patent to Polinlowsky No. 1,805,205), issuedJanuary 11, V1921. The first and second line finder switches 101 and 102and the group selector switch 306, 807, shown diagrammaticaliy in thepresent disclosure, may also be of the same type as the correspondingswitches shown in the above application.

At the time of the seizure of the register sender by the senderselector, relay 208 is energized by means of a circuit closed frombattery through its left-hand winding, contact 212 (l), and conductor303 to ground at the tirst group selector. r1`he manner in which thisground is placed uponl the conductor 8051 is fully explained in theabovementioned application. Relay 208 closes a circuit through itsright-hand winding tor driving sequence switch 220 into position f5, ()nleaving position 2 sequence switch 220 opensl at its contact 212 thecircuit ot the lett-hand winding otE relay 208 and the right-handwinding ot relay 205 being shunted by the master contact 224 betweenpositions 1 and 3 of sequence switch 220, relay 208 deeneii'gizes.Sequence switch 220, therefore, comes to rest in position Il. A circuitis now closed from battery through the contact 21-t (3), winding ofrelay 200, to ground, at the back contact and armature of relay 208.Also in position 3 of sequence switch 220 the primary winding ot thedialing tone coil 241 is closed in series with the interrupter 242 atthe contact 243. A characteristic tone is thereby transmitted over theconductors 202, 203 and 103 and 101- to the receiver at the callingsubscribefs station. 'lhe circuit over which this dialing tone is sentto the substation and which constitutes the impulse circuit. t'orcontrolling the setting of the register sender, is closcd at this timeby sequence switch contacts 200 and 201 belonging to the controllingsequence switch (not shown) of the group selector. In position 3 ofsequence switch 220 the stepping relay 225 energizes in series with thecalling line and closes a circuit from ground over the armature andfront contact of relay 225, armature and front contact of relay 20G,contact 244 (3), right-hand winding and armature and contact of relay207, contact 209 (fi), winding of the tens thousands register 400 tobattery and ground. At the same time a parallel circuit is closedthrough tue le ft-hand winding of relay 207 to ground at the armatureand front contact of relay 225. The relay 207 is differential in itswinding so that when both of the above-traced circuits are closed at thesame time this relay does not attract its armature. The register 400,however, energizes and moves out of position 0. Between position 0 andposition 1 the master contact 403 of register 4100 closes a shuntcircuit around the right-hand winding of relay 40T. This relay,therefore, energizes over its left-hand winding and attracts itsarmature. The register 400 continues under the control ot' its mastercontact into position 1. The, calling subscriber hearing thecharacteristic tone in his receiver manipulates his impulse transmitter133 to send the first series of impulses to the register sender. On thefirst interruption of the line circuit, the stepping relay deenergizesand opens the circuit of the left-hand winding of relay 20T, permittingthis latter relay to release its armature. On the next closure of theline circuit and the consequent operx ation of relay the above-tracedcircuit is closed for the register 400. Register 400 advances fromposition 1V into position 2 and ditt'erential relay 20T is againenergized. This method of operation continues, the tens thousandsregister 4100 advancii'ig through one position t'or each interruption otthe line circuit during the transmission ot the tirst series ofimpulses. The calling subscribers impulse transmitter 133 is soconstructed that the last interruption of the line in each series is ofcomparatively longer duration than the preceding interrul'itions. Henceon the last interruption the relay 225 maintains its armature retractedfor a comparatively longer interval than on the pre-- cedingreti-actions. The circuit which leads from battery through the windingsof relay 205, contact 213 to ground at the back contact and armature ofrelay is therefore closed for a time sutlicient to permit theenergization of relay 205. Relay 205 is otl the slow-to-energize typeand does not operate in response to short closures otI its circuit. Therelay 205 closes a circuit tor relay 208 which in turn completes acircuit through its right-hand winding, as above described, for drivingsequence switch 220 out of position 3 and into position Relay 205deenergizes as soon as sequence switch 220 opens its contact 213 andmoves into position 3 and the calling line is closed at the substationto energize relay 225 before contact 213 is again closed in positionTherefore, relay 205 remains deenergized and sequence 220 stops when itreaches position 5. In moving from position 3 into position 5 sequenceswitch 220 at its contact 200 shifts the control of the stepping` relay225 from the tens thousands register 400 to the thousands register 500.

A circuit is now completed from ground over the armature and frontcontact of relay 225 armature and front; contact of relay 206, contact402 of register 400, righthand winding and armature and contact ot relay20T, contact 209 (5), winding ot register 500 to battery and grround.'lelay 207 does not operate since both of its windings are energized.The thousands register 500, however, advances from position 0 intoposition 1. )Vlien passing' from position 0 to position 1, the mastercontact ot this register shunts the right-hand winding of relay 207 andsaid relay attracts its armature. )Vlien the calline' subscriber'operates his dial tor the second series ot impulses, the stepping relay225 deenergizes at each interruption otl the line. Relay 20T on thefirst interruption of the line, deenergizes, and upon the nextattraction of the armature ot relay 225, the thousands register 500 isadvanced t'rom position 1 into position 2. In this manner the thousandsregister is driven to a position corresponding.r to the, number otimpulses sent in the second series. At the end of the second series otimpulses the slow-to-energize relay is operated and closes the circuitot relay 20S. Relay 20S closes the circuit for drivingr sequence swit'ch220 out of position 5 and into position 8.

ln position 8 ot sequence switch 220 the hundreds register 000 is placedunder the control of the stepping relay 225. The circuit tor operating'the register 000 may be traced from ground over the armature and frontcontact o1 relay 225, armature and front contact ot relay 206, contact402, right-hand winding and armature and contact ot relay 207, contact210 (8), winding of the hundreds register 600 to battery and y`q'round.In the same manner as described in connection with the first tworegisters 400 and 500, the hundreds register G00 is driven step-by-stepunder the control of the stepping; relay until it reaches a positioncorrespoi'idingl' to the number ot impulses in the third series. .f'ttthe last comparatively long' impulse ot' this series, theslowtti-energize relay 205 attracts its armatures and the sequenceswitch 220 is driven from position 8 into position 10.

1n position 10 ot sequence switch 220 a. circuit is completed fromground to the armature and front contact ot' relay armature and frontcontact` ot' relay 206, contact 402, right-hand winding and armature andcontact ot relay 207, contact 210 (1.0). winding ot the tens register700 to battery and ground. For each impulse transmitted in the tensseries the register 700 is moved forward one position. At the last'interruption of the line in the tens series the slow-toenergize relay205 attracts its armature and closes a circuit tor relay 208 which inturn completes a circuit for driving' sequence switch 220 out otposition 10 and into position 12. ln this position the following circuitis closed for the units register 800': ground, over the armature andfront contact of relay 225, armature and Jfront c-ontact of relay 206,contact 402, righthand winding and arn'lature and contact ol. relay 207,contact 211 (12), winding' oi" the units register 800, to battery andground. The calling subscriber now sends the tinal series ot impulsesand the units register is set up to a position corresponding to 'thenumber of interruptions produced in the line during the transmission ofthis series. At the last interruption of the line circuit the relay 205is again energized and sequence switch 220 advances from position 12into position 14. On reaching' position 1l thc sequence switch 220 isimmediately driven into position 15 as soon as relay 225 becomesdeenergized by means ot' the following circuit: battery, through thewinding ot sequence switch 220 contact 215 (14), bach contact andarmature ot relay to ground. The relay 225 is deenerg'ized at this timein a maner to be explained hereinafter.

lYhen the calling' subscriber has completed the setting' of the t'irsttwo registers, at which time the sequence switch 220 moves trom position5 into position S, the irst group selecting' operation is proceededwith, without waiting for the remaining' registers 'to be positioned. Assequence switch 220 reaches position 0 it closes the following eircuitto drive sequence switch S10 out ol position 1 and into position 3:battery. through the winding of sequence switch 310, contact $511contact and right-hand armature of relay 312, contact 401 of register400 to ground at contact 245 ot sequence switch 220. In position 3 ofsequence switch 310 the fundamental circuit tor cont 'olling the brushselection at the irst 2Q'roup selector is closed. This circuit may betraced t'rom ground over contact B13 (Il), contact and armattn'e otrelay 314, winding o'i' the stepping' relay 315. contact 310 (Il), overthe conductor 301 to tht` usual control relay (not shown), at the lirstgroup selector. lt not thought necessary to lQ'ive a coieipletedescription ot the operation ot the register sender in its control otthe group and linal selector switches. lt is suiicient to observe thateach of the several registers 400, 500` 600, 700 and 800 is driven backto its normal position from the position to which it was set by thecalling' subscril'ier to control the successive selective operations inthe ex tension of the call through to the called subscribers line 300.This register sender ot the same type and -operates in the same manneras the` register sender shown in the above-mentional patent No.1,305,200, issued January 11, 1921. It may be noted that while sequenceswitch 310 is passing from position 12 to position 15 it closes thetollowing circuit for energizing relay 249:

ground, contact 323 (2-1-14), lett-hand armature and back contact otrelay 330, contact 331 (13), thence through the winding of relay 249 tobattery. Relay 249 operates and at its right back contact opens thecircuit of relay 225. Relay 225 releases and closes the circuithereinbetore traced tor driving sequence switch 220 out ot' position 14.

After the switches have been up and the connection established to thecalled line the holding circuit ot the stepping relay is opened atcontacts 200 and 201 by the adrance, in the usual manner, ot thesequence switch controlling the circuits ot the tirst group select/or.At the same time the registers 400, 500, 600, 700 and 800 having allbeen restored to their normal positions. the sequence switch 310 isdriven into position 15. In position 15 ot sequence switch 310 a circuitClosed trein battery through the winding of sequence switch 310, contact317 (15), contact 404 (0), contact 501 (0). contact 318 (15), contact319 (15), contact (301 (0), contact 320 (15). to ground at contact 24o(15) Sequence switch 310 moves out ot position 15 and into position 1owhere a circuit is closed from gr-ouild through the winding' ot sequenceswitch 310, contact 311 (1(5), contact 701 (0), contact 321 (1G), toground at contact 246 (15). Sequence switch 310 is driven from position10 into position 17 where a circuit is closed trom battery through thewinding of sequence switch 310, contact 31.1 (17), contact 801 (0), bachcontact and armature of relay 322, contact 802 (0). contact 321 (17). toground at contact 2.10 (15). Sequence switch 310, therefore. moves`t'rom position 17 into position 1. In position 1 of sequence switch 310a circuit is completed from bat' tcry through the lett-hand winding ot'relay 203, contactv 212 (15). contact 323 (1), to grouml. Relay 208energizes and coinpletes a circuit for drivineV sequence switch 320 intoposition 17. In position 17 relay 205 is energized by means of a circuitincluding contact 213 (17), back contact and armature of relay 206, andcontact 210 (17). Relay 205 attracts its armature and closes a circuittor relay 208 which in turn completes a circuit 'tor dl'iving sequenceswitch 220 out ot position 17 and into position 1. The register senderhas now been completely restored to its normal position and may be takenin connection with the extension of subsequent calls.

The case will next bc considered in which the 'alling subscriber havinginitiated a call and obtained a register sender, is nnable to -completethe desired connection either because the sender vtails to functionproperly or because 11e is unable to transmit impulses to the exchange.Upon the removal oi his receiver trom the hook and the extension of hisline through to the irst group selector, the relay 203 is enen gized inthe manner above explained and sequence switch 220 advances intoposition 3. In the regular operation ot the sender the sequence switch220 only remains in position 3 for a brief interval; being driven out ofthis position and into position 5 as soon as a series ot' impulses hasbeen sent trom the calling substation. In passing through position 2sequence switch contact 21S) closes a circuit tor the right-hand windingot relay 222. Relay 222 attracts its armature and closes a lockingcircuit from battery over contact 231 of sequence switch 230 (closing insome position from 1 to 10), lett-hand winding and arn'iature andcontact of relay to ground at contact 221. On reaching position 3,sequence switch 220 closes a circuit from battery through the winding'of relay 33, contact 218 (3), interrupter 232. to ground. On the firstclosure of the interrupter 232, relay 233 energizes and completes acircuit from battery through the winding of sequence switch 230, contactand armature and right-hand winding ot' relay 234 to ground at the frontcontact and armature ot relay 233. A circuit is also closed in parallelthereto for the lett-hand winding of relay Relay 234 being ditterentialdoes not operate since both et its windings are simultaneously'energized. Sequence switch 230, however, advances from the position inwhich it happens to bc standing to the next succeeding position. dienthe master contact 2.47 closes. the right-hand winding ot relay 2311Y isshunted out and this relay attracts its a1'- mature, thus opening theenergizing circuit ot' sequence switch 230. As soon thereafter as theinterrupter reaches an insulating segment relay 233 deenergizes andopens the circuit ot' the left-hand winding ot relay 234, permittingthis relay to release its armature. As the interrupter 232 reaches itsnext ccnlducting segment relay 233 energizes and sequence switch 230 isdriven torward another position. 'lhis operation continues untilsequence swit-cl. 230 moves troni position 10 into position 1. 0nleaving position 1G, contact 231 is opened and relay 222 dccnergizes.Sequence switch 230 continues to advance until it reaches position 11where a circuit is completed Yfrom battery over sequence switch contact23 (t1). lett-hand winding ot relay 223, back contact and a mature ot'relay contact 221 (3). to ground. Relay 223 attracts its arniatm'er'`and closes the following circuit: battery. over the left-hand armatureand contact ot' relay 223, conductor 134, contact 135 (1) of sequenceswitch 130, left-hand winding ot relay 113 to ground. Relay 113energizes and closes a circuit from ground over its armature and frontcontact and contact (1) for driving sequence switch 130 out ot' position1 and into position 3.

The brush carriage ot' the hunting switch carrying the brushes 127, 128,129, 131 and 132 is now rotated to advance its brushes over the terminalbank in search ot the particular register sender that has been taken toruse by a calling line and tailed to advance in the regular manner. Thecircuit for the power magnet 121. which controls the operation of thebrush carriage, leads from battery through the winding of said magnet,contact 122 (3), back contact and armature ot' relay 126 to ground atthe front contact and armature otI relay 113. Yhen the lmnting switchreaches the third set otterminals in its terminal bank. the brush 129makes contact with terminal 240 and the following circuit is closed:ground over contact 117 (3), brush 129, terminal 240, conductor 136,contact 137 ot ke v 105 at the operators position, winding ot relay 106,contact 138 et' key 105, conductor 139, contact 140 (3), resistance 141.to battery and ground. Relay 106 attracts its armature and completes acircuit from battery through the winding ot sequence switch 120. contact and armature and lett-hand winding of relay 107 to ground atcontact and armature ot relay 106. ln parallel to this circuit a circuitis closed from battery through the right-hand winding ot relay 107 toground at the contact and armature of relay 106. A circuit is alsoclosed from battery through the winding ot relay 108, contact andarmature and left-hand winding ot relay 107 to ground at contact andarmature of relay 106. The relay 107 is ditterential and therefore doesnot operate when both ot its windings are energized. Sequence switch 120energizes and passes trom position 1 into position Between positions 1and 2 the master contact ot sequence switch 120 short circuits thelcit'thand winding ot relay 107, permitting this relay to energize.Relay 108 remains energized by means ot' a circuit closed by the mastercontact of sequence switch 120 until said sequence switch reachesposition 2. Relay 108 maintains an energizing circuit t'or theright-hand winding ot relay 107, inde` pendent of the armature andcontact ot relay 106, to prevent the deenergization ot relay 107 untilsequence switch 120 has had time to advance into position Vln themeantime the brush 12S) oit the limiting switch leaves terminal 240 andafter sequence switch 120 has reached its` second position the relay 107deenergizes.

Vhen the hunting switch advances its brushes 127, 128. 12S) and 131ontoltlie terminals 226, 227, 228 and 229, a circuit is closed frombattery over the right-hand arn'iature and contact of relay 223,terminal 229, brush 131, contact 118 left-hand winding of relay 119 toground. Relay 119 attracts its armature and closes a circuit through itsright-hand winding and the winding of relay 126 to ground. Relay 126becomes energized and opens the abovetraced circuit for the power magnet121, causing the hunting switch to come to rest. Relay 126 also closes acircuit from ground through the armature and front contact ot' relay114, armature and front contact ot relay 136, contact 124 (3), windingot sequence switch 130, to battery and ground. Sequence switch 130energizes in this circuit and moves from position 3 into position 5. Inposition 5 of sequence switch 130, relay 113 is maintained energized bymeans ot a circuit from battery through the righthan l winding of saidrelay, contact 140 (5), conductor 139, contact 138 of key 105, relay106, contact 137 of key 105, conductor 136, contact left-hand winding ofrclay 113 to ground. Relay 106 being marginal does not energize inseries with the windings of relay 113.

Since the register sender that has been associated with the operatorsposition is the first one appearing in the terminal bank ot the huntingswitch only one of the advance terminals, such as 240, is passed over bysaid switch. Consequently, the sequence switch 120 at the distantexchange has been advanced through one position only. Had the registersender seized by the limiting switchibeen the second, third or fourthvsender of the group, for example, the sequence switch 120 would havebeen advanced through 2, 3 or 4 positions respectively. At eachdeenergization of the relay 108 in the advance ot' sequence switch 120,a momentary circuit is closed after said sequence switch reachesposition 2 tor the relay 10S). The relay 109 is slo\\'-to-energize anddocs not operate on short closures ot' its circuit. After relay 108ceases to operate and relnains permanently deenergized, relay 10S)attracts its armature and closes a circuit tor the particular indicatinglamp that has been selected by the sequence switch 120. ln the caseassumed, the lamp 142 which designates the [irst sender of the group islighted by means ot a circuit from battery through said lainp, contact143 (2) ot' sequence switch 120, contact and armature ot relay 109 toground. A signal lamp 111 is also illuminated in a circuit closed atcontact 110 as soon as sequence switch reaches position 2. The operatorobserving the lamp 111, knows that a sender is being associated with herposition; also observing that' the lamp 142 is lighted, she knows thedesignation ot the particular sender involved. i The operator thereupondepresses the key 105 which connects her telephone set to the trunkconductors 136 and 139. The depres- Cil fil)

sion of the key 105 also opens the circuit of relay 113. 'Relay 113being deenergized closes a circuit from ground over its armature andback contact and contact 12.r (5), for driving sequence switch 130 outof position 5 and into position 7.

In this position a talking circuit is established between the callingsubscribers line and the operators position. Talking battery is suppliedto the calling line over the windings of relay 114, sequence switchcontacts 115 and 116, brushes 127 and 128, terminals 226 and 227, andconductors 202 and 203. The relay 204 is energized in the seventhposition of sequence switch 130 in a circuit jfrom ground through thewinding of said relay, terminal 123` brush 120, contact 11T (T),resistance 141, to battery and ground. The relay 204l disconnects thecalling subscribers line Vfrom the winding of stepping relay 225 andconnects the windings of said relay to the conductors 144 and 145leading to the operators position in the distant exchange. The operatorconverses with the calling subscriber and obtains from him the number ofthe line with which he desires connection. Assuming that the callingsubscriber is unable to transmit impulses to the exchange, the operatormay then manipulate her impulse sender 146, in accordance with thedesignation she receives t'roni the (,alling party. The operation o1 theimpulse sender 146 causes impulses to be sent to the stepping relay 225of the selected register sender. The circuit tor the transmission ot'these impulses may be traced. trom battery through the lett-hand windingot' relay 225` `l'roiit contact and left-hand arn'iature ot relay 204,conductor 145, contact 147 of key 105. impulse sender 146. contiact 143ot' key 105. conductor 144, rightband armature and tront contact otrelay 204, right-hand winding ot'v relay 225. back contact andright-hand armature of relay 219 to ground. A t'ter the register senderhas thus been positioned by means ot the operators impulse sender, itproceeds in the regular manner to control the operation ot the selectiveswitches to establish the desired connection between the calling andalled lines. Yhen the operator has completed the setting of the registersender she releases lier key 105, which closes theI above-traced circuittor relay Y113 and relay 106. rl`he relay 113 energizes and completes acircuit from ground over its armature and Yfront contact, contact 125(T). winding ot" sequence switch 130, to battery and ground. 'lhesequence switch 130 thereupon moves out of position 1' and into position9. In leaving position 7. contacts 135 and 140 are opened to permit thedeenergization of relay 113. In position 9 of sequence switch 130 acircuit is established for the power magnet 121, traceable from batterythrough the winding ot' said magnet, Contact 122 (9), back contact andarmature of relay 113, to ground. The brush carriage of the huntingswitch commences t0 rotate. lVhen the brush 129 engages the terminal 241a circuit is closed from ground over contact 11T (9), brush 129,terminal 241, conductor 136, contact 137 of key 105, winding of relay106, contact 138 of key 105, conductor 139, contact 140 (0), resistance141, to battery and ground. The relay 106 energizes in this circuit andcauses the advance of sequence switch 120 ytrom position 2 into position3 in the manner above explained. Upon the brush 120 engaging theterminal 243, relay 106 is again energized and sequence switch 120nieves to another position. Likewise for each set otl terminalsrepresenting a register sender in the terminal bank of the huntingswitch, the indicating switch 120 is moved one position Jforward. Theindicating switch 120 will be provided with as many positions there areregister senders represented in the terminal bank in the hunting switchso that when said limiting switch is restored to its normal position,the switch 120 will also have reached its normal position. As thelimiting switch restores to its normal position, the brush 131 engagesthe grounded contact 239. A circuit is then closed from ground over saidcontact and brush, sequence switch contact 113 (El), rightliand windingof relay 113, to battery and ground. Relay 113 energizes and opens thecircuit ot the power magnet 121, causing the brush carriage of thehunting switch to cease to rotate. Relay 113 also closes a circuit troniground over its armature and front contact, contact 125 (0), winding ot'sequence switch 130 to battery and ground. Sequence switch 130 movestroni position 0 into position 1. 'lhe hunting switch and all apparatusconnected therewith for associating the register senders with theoperatoi"s position has thus been restored to its normal position.

The timing mechanism shown within the broken rectangle at the lowerlet'tdiand corner of Fig. 2 is common to all register senders to whichthe limiting switch has access. As above explained` when any one otthese register senders is connected to a calling line, sequence switch.220 iniuieiliatelji' passes into posit-ion 3. ltimpulses arc sent tothe register sender without delay the se queuce switch 220 advances outof position 3 before the timing sequence switch 230 can reach positionl1 to initiate the operation of the hunting switch. )Then sequenceswitch 220 remains in position 3 for a longer period of time thanrequired in its regular operation, the common timing apparatus 230starts the hunting switch to search out the particular register senderwhile sequence switch 220 is standing in position 3 and associates thesame with the operators position.

vhat is claimed is:

1. In a telephone system, a subscribers line, selective switches forextending` said line, a plurality of register senders coinmon to saidswitches for controlling the selective movement thereof, means forconnecting' the subscribei"s line to one of said senders and forcom'iecting the sender to one ot said switches, an operators position,and means common to said senders for automatically associating theparticular sender to which said line is connected with the operatorsposition.

2. ln a telephone syst-em, a subscribers line, selective switches forextending said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting the subscribers line to one of said senders and forconnecting the sender to one of said switches, means controlled oversaid line for setting said sender, an operator`s position, means commonto said senders for automaticallyv associating the particular sender towhich said line is connected with the operator-s position, and meanscontrolled by the operator for setting said sender.

3. ln a telephone system, a subscribefs line. selective switches forextending' said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting the subscribers line to one of said senders and forconnecting' the sender to one of said switches, means for sendingimpulses over said line to register a desired designation on suchsender. an operator`s position, means common to said senders forautomatically associating the particular sender to which said line isconncoted with the operators position, and means controlled by theoperator for registering' designations on said sender.

4. in a telephone system, a subscriber`s line. selective switches forextending said line. a plurality of register senders common to saidswitches for controlling the selective movelnent thereof. means t'orconnecting' the subscrihens line to one otl said senders and t'orconnecting the sender to one of said s\\'itches. an operator`s position.and means common to said senders operative at the end otl a detiniteinterval after the connection of said line to one of said senders forassociating such sender with the operators position.

:3. In a telephone system, a subscribei"s line, selective switches forextending said line, a plurality of register senders coinmon to saidswitches for controlling' the selective movement thereof, means forconnecting a subscribers line to one of said senders and tor connectingthe sender to one of said switches, means controlled over said line forsetting said sender, an operators position, means common to said sendersoperative at the end of a delinite interval after the connection of saidline to one of said senders for associating such sender with theoperators position, and means controlled from the operators position forsetting said sender to control said switches.

6. In a telephone system, a subscribe1"s line, selective switches forextending' said line, a plurality of register senders common to saidswitches for controlling` the selective movement thereof, means forconnecting said line to one of said senders and for connecting thesender to one of said switches, an operator`s position, and anautomatically operated switch common to said senders for associating theparticular sender to which the subscribers line is connected with theoperatoris position.

7. In a telephone system, a subscribers line, an impulse transmitter insaid line, selectit'e switches for extendingr said line, a plurality ofregister senders common to said switches for controlling the selectivemovement thereof, means for connecting said line to one of said sendersand for connecting the sender to one of said switches, means controlledby said impulse transmitter for setting said sender` an operatorsposition, an automatically operative switch common to said senders forassociating the particular sender to which the subscribers line isconnected with the operator`s position, and means for sending impulsesfrom the operator`sA position to srt said sender.

8. ln a telephone system, a subscribens line, selective switches forextending said line, a plurality of register senders common to saidselective switches, for controlling' the selective movement thereof.means for connecting' said line to one ot said senders and forconnecting' the sender to one of said switches, an operators position. ahunting switch connnon to said senders, and means for automat icaliyoperating' saifl hunting switch at the end ot a predetermined intervalat'ter the connection of said line with a register sender, said switchheing' arranged to select said sender and associate the same with theoperators position.

t). In a telephone system. a suhscribel"s line, selective switches forextending said line, a plurality of register senders common to saidselector switches for controlling the selective movement thereof, meansfor connecting` said line to one of said senders and for connecting thesender to one of said switches, an operatons position, a limiting'switch common to said senders, means for automaticaily operating saidhunting switch at the end of a predetermined interval after theconnection of said line to the register sender, said switch beingarranged to select said sender and associate the saine with theoperator`s position, and impulse-sending means at the operators positionfor setting said sender in accordance with a desired designation.

1t). In a telephone system, a subscribers line, selective switches forextending said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting' said line to one of said senders and for connecting thesender to one of saidA switches, an operators position, a hunting switchcommon to said senders, a timing device arranged to operate in cycles,and means controlled by said device at the end of its cycle for startingsaid hunting switch, said switch being arranged to select the particularsender to which said line is connected and associate the same willi theoperators position.

1.1. In a telephone system, a subscribers line, selective switches forextending said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting said line to one of said senders and for connecting thesender to one of said switches, an operators position, a hunting switchcommon to said senders, a timing device arranged to operate in cycles,means for initiating the operation of said device when said line isconnected to one of said senders, and means operated by said device atthe end of its cycle for starting said hunting switch, said huntingswitch being arranged to select the particular sender to which thesubscribers line is connected and associato the same with the operationsposition.

l2. yln a telephone system, a subscribc1"s line. selective switches forextending said line, a plurality ot register' senders coniuion to saidswitches for controlling the selective movement thereof, means l'orcounccting said line to one of said senders and for connecting thesender to one of said switches, means under the control of thesubscriber for setting such sender, an operators position, a huntingswitch common to said senders, a timing device arranged to operate incycles, means for initiating the operation of said device when said lineis connected with one of said senders, means operated by said device atthe end of its cycle for starting said hunting switch, said huntingswitch being arranged to select the particular sender to which thesubscribers line is connected and associate the same with the operatorsposition, and means for placing the setting of said sender under thecontrol of the operator.

It. In a telephone system, a subscribers line, selective switches forextending said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting said line to one of said senders and for connecting thesender to one of said switches, an operators position, switching meansconnnon to said senders for automatically associating the particularsender to which said line is connected with the operators position, andcircuits controlled by said switching means for establishing a talkingconnection between said subscribers line and the operators position.

14. In a telephone system, a subscribers line, selective switches forextending said line, a plurality ot' register senders common to saidswitches for controlling the selective movement thereof, means forconnecting said line to one of said senders and for connecting thesender to one of said switches, means controlled from the substation ofsaid line for setting said sender, an operator-s position, switchingmeans common to said senders for automatically associating theparticular sender to which said line is connected with the operatorsposition, circuits controlled by said switching means for establishing atalking connection between said subscribers line and the operatorsposition, and means controlled from the operators position for settingsaid sender.

15. In a telephone system, a subscribers line, selective switches forextending said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting the subscribers line to one of said senders and forconnecting the sender to one of said switches, an operators position, ahunting switch common to said senders, means operative at the end of agiven time interval after tho connection of said line to one ol' saidsenders for starting said hunting switch, said huntingI switch beingarranged to associate such sender with the operators position, andcircuits controlled by said hunting switch for establishing a talkingconnection between said subscribers line and the operators position.

16. In a telephone system, a subscribers line, selective switches forextending said line, a plurality of register senders for controllingsaid switches, means for connecting said line to one of said senders, anoperator-s position, means common to said senders for automaticallyassociating the particular sender to which said line is connected withthe operators position, and an indicating device for indicating to theoperator the designation of the sender that has been associated with herposition.

1.7. In a telephone system, a subscribers itt() line, selective switchesfor extending said line, a plurality of register senders for controllingsaid switches, means for connecting said line to one of said senders, anoperators position, means common to said senders for automaticallyassociating the particular sender to which said line is connected withthe operators position, and a selectively operable indicating device forindicating,` to the operator the designation of the sender that has beenassociated with her position.

18. n a telephone system, a suhscriloers line, selective, switches forextending said line, a plurality of register senders for controllingsaid switches, means for connecting said line with one oll said senders,an operators position, an automatic switch common to said senders, meansfor operating said automatic switch to select the particular sender towhich the subscribers line is connected and associate the same with theoperators position, a plurality of indicating detvices, and a selectiveswitch for selecting said devices to indicate to the operator thedesignation of said senders, said last-named switch being arranged toadvance automatically in response to the operation of said automaticswitch.

19. In a telephone system, a suhscribefs line, selective switches forextending said line, a pluralityY of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting,r the subscribers line to one of said senders and forconnecting` the sender to one of said switches7 an operators position,and means operative at the end of a definite interval after theconnection of said line to one of said senders for associating said linewith the operators position.

2t). In a telephone system, a subscribers line, selective switches forextending said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting the subscribers line to one of said senders and forconnecting the sender to one of said switches, means controlled oversaid line for setting said sender, an operators position, and meansoperative at the end of a definite interval after the connection of saidline to one of said senders for associating' said line with theoperators position. y

21. In a telephone system, a suhscribers line, selective switches forextending said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting the subscrihers line to one of said senders and forconnecting the sender to one of said switches, an operators position,means operative at the end of a definite interval after the connectionof said line to one of said senders for associating said line with theoperators position, and means for indicating' to the operator that aline has become associated with her position.

22. In a telephone system, a suhscrihers line, selective switches forextending` said line, a plurality of register senders common to saidswitches for controlling the selective movement thereof, means forconnecting the subscribers line to one of said senders and forconnecting1 the sender to one of said switches, an operators position,and automatic switching means operative at the end of a definiteinterval after the connection of said line to one of said senders forassociating said line with the operators position.

In witness whereof, I hereunto subscribe my name this 13th day ofOctober A. D., 1919.

LIPA POLI NK( )VS K Y.

